I am looking for the correct english term that can best be explained as follows:
You are producing clothes. One day you get the wrong color on the fabric that you have ordered, and thus you need to create a report about this error.
What is this report called? Deviation report? Aberration? Disparity? Something else?
(What I’m looking for in Swedish is “Avvikelserapport”, if some Swede sees this and immediately knows the correct term.)
I would go with what @geoffaire has suggested.
Also I would have a look into the contract between you, and your subcontractor. Often there are certain terms used in those contracts, that should be also been used with the complaint.